Lock washer



Nov. 27, 1934. c. .1. SPAHN 1,982,076

LOCK WASHER Filed April 10, 1934 mi "u INVENTOR C. J. S/JCt/ZIZ-ATTORNEY Patented Nov. 27, 1934 UNETED STATES LOCK wssmm Chester J.Spahn, Folsom, Calif., assignor of onehalf to James H. Cavitt, Folsom,Calif.

7 Application April 10, 1934, Serial N 719,865

1 Claim.

This invention relates to lock washers for bolts, and particularly forbutton head carriage bolts such as are used in connection with woodenparts and which are prevented from turning in the wood by the squaredshank portion immedi ately under the head and driven into the wood.

It sometimes happens however, especially when the bolts are drawn uptight, when in soft wood, or when the bolt hole is relatively large andprovides little stock for holding engagement with the spared portion,that the bolts turn or the heads become drawn into the wood. This eitherprevents the proper tightening up of the nut or in the event of the headultimately drawing into the wood, causes the parts tied together by thebolt to become loose relative to each other.

The principal object of my invention therefore is to eliminate theseundesirable occurrences by the provision of a simple and inexpensiveform of lock washer for bolts of this character designed to bothpositively prevent rotation of the bolt and also the drawing of the headof the same into the wood.

The above object I attain by means of such structure and relativearrangement of parts as will fully appear by a perusal of the followingspecification and claim. 1

In the drawing similar characters of reference indicate correspondingparts in the several views:

Figure 1 is a diametral section of a washer as applied about a carriagebolt shown mounted in connection with a wooden beam.

Figure 2 is a perspective view of a two-prong washer.

Figure 3 is a similar view of a three-prong washer.

Figure 4 is a similar view of a modified form of washer.

Referring now more particularly to the characters of reference on thedrawing, the type of bolt to which my improved washer is designed to beapplied comprises a shank 1 having a button head 2 and a square portion3 immediately under the head whose width across the flatsis thesame asthe diameter of the shank, so that the corners of said portion projectbeyond the periphery of the shank for engagement with the wood 4outwardly of the bolt hole 5.-

The washer as shown in Figures 1 and 2 comprises a circular body 6larger than the bolt head having a square hole 7 tofit the shank portion3. Depending from the body at opposed points outwardly of the peripherythereof and at an outward angle to the axis of the bolt and washer 4also to the turning of the same.

are stiff sharp pointed prongs 8. These draw into the wood as alongitudinal pulling pressure is placed on the bolt and prevent the boltfrom turning without relying on the'engagement of the squared portion 3with the wood. The angular setting of the prongs relative to thedirection of axial movement of the washer, and the placing of the sameoutwardly of the periphery of the body of the washer adds to theresistance of movement of the washer into the wood and A bolt equippedwith a washer of this character therefore is practically held immunefrom any rotative or axial movement once the nut has been properly.tightened. v

The construction in Figure 3 is the same except that the washer body 6ahas three evenly spaced prongs 8a; this type of washer being preferablyused in connection with relatively large bolts or where the wood isquite soft.

The type of washer disclosed in Figure 4 is the same generally as eitherof the above described types, but instead of the prongs the washer body6b has a plurality of short spikes 9 depending therefrom inwardly of theperiphery of the body and in evenly spaced relation about the boltopening asplainly shown.

From the foregoing description it will be readily seen that I haveproduced such a device as substantially fulfills the objects of theinvention as set forth herein.

While this specification sets forth in detail th present and preferredconstruction of the device, still in practice such deviations from suchdetail may be resorted to as do not form a departure from the spirit ofthe invention, as defined by the appended claim;

Having thus described my invention what I claim as new and useful anddesire to secure by

